Guide
Substances of Very High Concern obligations
How to comply with UK REACH obligations for Substances of Very High Concern (SVHCs). Covers the Candidate List, notification requirements, supply chain communication duties, authorisation, restrictions, and how the UK and EU SVHC lists are diverging.
Substances of Very High Concern (SVHCs) are chemicals that can cause serious and often irreversible effects on human health or the environment. Under UK REACH, SVHCs are identified and placed on the Candidate List, which triggers specific obligations for all businesses in the supply chain.
Understanding your SVHC obligations is essential whether you manufacture, import, formulate, distribute, or use chemical substances or articles in Great Britain. Non-compliance is a criminal offence with significant penalties.
What makes a substance an SVHC
A substance qualifies as an SVHC under UK REACH Article 57 if it meets one or more of these criteria:
- CMR - Carcinogenic, mutagenic, or toxic to reproduction, meeting the criteria for classification in Categories 1A or 1B under GB CLP
- PBT - Persistent, bioaccumulative, and toxic, meeting the criteria set out in UK REACH Annex XIII
- vPvB - Very persistent and very bioaccumulative, meeting the criteria set out in UK REACH Annex XIII
- Equivalent concern - Substances for which there is scientific evidence of probable serious effects to human health or the environment giving rise to an equivalent level of concern (e.g. endocrine disruptors)
The UK REACH Candidate List
The Candidate List is the formal register of identified SVHCs. Inclusion on the Candidate List triggers immediate obligations and may lead to the substance being added to the Authorisation List (Annex XIV), which restricts its use further.
Notification requirements
If you produce or import articles containing Candidate List SVHCs, you must notify HSE when both of the following thresholds are met:
- Concentration threshold: the SVHC is present at above 0.1% weight by weight (w/w) in the article
- Tonnage threshold: you produce or import more than 1 tonne of the SVHC per year, summed across all articles containing it
You must notify HSE within 6 months of a substance being added to the UK REACH Candidate List. The notification must include:
- Your identity and contact details
- The registration number of the substance (if available)
- The identity of the substance (name, EC number, CAS number)
- The classification of the substance under GB CLP
- A brief description of the use of the substance in the article and the uses of the article
- The tonnage range of the substance (e.g. 1-10 tonnes, 10-100 tonnes)
Exemption: You do not need to notify HSE if you can exclude exposure of humans and the environment to the SVHC during normal and reasonably foreseeable conditions of use, including disposal. You must document this assessment and be able to provide evidence to HSE on request.
Supply chain communication duties
Suppliers of substances, mixtures, and articles containing Candidate List SVHCs have specific communication obligations:
Business-to-business communication
Under UK REACH Article 33(1), if you supply articles containing a Candidate List SVHC above 0.1% (w/w), you must automatically provide the recipient with:
- Sufficient information to allow safe use of the article
- As a minimum, the name of the SVHC
This duty applies at every stage of the supply chain. You do not need to wait for a request - the information must be provided proactively.
Consumer information rights
Under UK REACH Article 33(2), any consumer has the right to request information about Candidate List SVHCs in articles. If a consumer submits a request, you must respond free of charge within 45 days, providing at a minimum the name of the substance.
Safety Data Sheets for mixtures
If a mixture is not classified as hazardous but contains a Candidate List SVHC at 0.1% (w/w) or more in a non-gaseous mixture, you must provide a Safety Data Sheet on request from any business customer.
Authorisation requirements
SVHCs on the Candidate List may be prioritised for inclusion on the Authorisation List (Annex XIV). Once a substance is on Annex XIV, it cannot be used or placed on the GB market after its sunset date unless a specific authorisation has been granted.
Restriction compliance
Independently of the Candidate List and Authorisation List processes, SVHCs may also be subject to restrictions under Annex XVII. Restrictions can limit or ban specific uses of a substance without requiring an authorisation application.
UK and EU SVHC list divergence
Since 31 December 2020, the UK REACH Candidate List and the EU REACH Candidate List have been independent of each other. The practical implications for businesses are:
- Different lists: Substances added to the EU Candidate List after 31 December 2020 do not automatically appear on the UK list, and vice versa. The EU list has grown from 211 entries (at the point of separation) to 251 entries, while the UK list has not yet been formally updated.
- Dual compliance: If you supply products into both the GB market and the EU or Northern Ireland market, you must check both Candidate Lists and comply with both sets of obligations. Northern Ireland follows EU REACH under the Windsor Framework.
- Future UK updates: The UK government announced in December 2025 that it will review the interim principles for additions to the UK REACH Candidate List by December 2026 and update the list accordingly.
- HSE assessment: HSE is assessing substances added to the EU Candidate List since 2021 to determine whether SVHC identification is appropriate for UK REACH. This may result in some EU additions being adopted into UK REACH, but not necessarily all.